 Project overview  Project-specific success criteria  Block diagram  Component selection rationale  Packaging design  Schematic and theory of operation  PCB layout  Software design/development status  Project completion timeline  Questions / discussion

 Laser tag game system with a few bonuses: ◦ RF Communication ◦ Designed for outdoor use ◦ Multiple firing modes ◦ Video game style power-ups/shields  Challenges include: ◦ Long distance IR communication ◦ RF collision and communication protocol ◦ Battery power (especially for high current LED drive) ◦ Packaging to withstand high adrenaline gameplay ◦ Innovative bonus features

 An ability to wirelessly transmit a shot and receive a hit via Infrared  An ability to remotely enable and disable the gun/vest pair  An ability to control game operation using base station keypad  An ability to wirelessly communicate game statistics to base station via RF  An ability to provide user with local display of game information

 Microcontroller ◦ Free samples, contains all desired peripherals, well documented, many GPIO pins  Radio Frequency ◦ Extremely well documented, phone support, example prototyping boards, complete solution kit  Infrared ◦ Based on proven TV remote control technology, sample schematics available online, inexpensive  Keypad ◦ Standard, inexpensive 4x4 key array  LCD ◦ Inexpensive, backlight, low power, wide V range

 In Circuit Serial Programmable  48kB Program Memory, 2kB RAM  Internal Oscillator 7.37 MHz  6x PWM for IR transmission  1x SPI for Shift Register/LCD display  4x Input Capture for Keypad and IR detectors  10 bit, 1Msps ATD for RF Signal Strength  2.5 to 5V operating range  72mA max at 3.3V and 20MIPS

 Development kit with example PCBs, application notes, phone support, and multiple transceivers and antennas  Receive and transmit within one package  Serial bi-directional communication  Zero configuration  2.6 to 3.6V operating range  Typical supply current: 6-12mA

 Same proven technology from home entertainment device remotes  TSOP detector filters external sources of IR by only triggering on 56kHz  Designed for long distance communication  TSAL IR LED rated for 100mA continuous

Vest  Four Sensor Pods  Status LEDs  Heavy-Duty Fabric Gun  PCB Housing  IR Transmitter  LCD Screen

 RF Ground Plane  Durable  LCD Screen  Keypad

 Base Station ◦ Microcontroller ◦ Keypad encoder ◦ Keypad  Allow user input ◦ Shift Register ◦ LCD Screen  Displays game stats ◦ RF Transceiver  Communicates with gun/vest pairs Base Microcontroller External DeviceFunctionPin # Programming HeaderPGC clock input1 PGD - data input/output44 /MCLR - Master Reset18 VDD40 VSS39 Shift RegisterSDO1 - SPI Data out44 SCK143 LCD ScreenRE5 - LCD Enable8 RF0 - Register Select5 Key EncoderRE4 - output enable9 RE3 - Data out D10 RE2 - Data out C11 RE1 - Data out B14 RE0 - Data out A15 IC7 - Data Available23 RF TransceiverAN3 - RSSI22 RB0 - Data19 RB1 - T/R Select20 RB2 -Power down21

MM74HC164 Shift Register 8-Bit Serial-in/Parallel-out Typical operating frequency: 50MHz Typical propagation delay: 19ns (clock to Q) NHD ‐ 0224BZ ‐ FL ‐ GBW LCD Screen 2 lines x 24 characters Transflective Yellow/Green LED backlight Potentiometer allows for change in contrast of screen

MM74C Key Encoder Key bounce elimination with capacitor Low power consumption On-chip row pull-ups

Pin 4 – Receive Signal Strength Indicator Pin 7 – Data line will output received data when in receive mode and will be a data input when in transmit mode Pin 8 – Transmit and receive select Pin 9 – Power down when low

Gun Microcontroller Shift Register LCD Screen Displays game stats RF Transceiver Communicates with base station IR LED Pulses IR signal as a shot Laser Diode Visual cue to aim Trigger Batteries Vest Color LEDs Simulates the status of the player and distinguishes between teams IR Receiver Receives signal of IR pulse and sends to gun microcontroller

Portable Microcontroller External DeviceFunctionPin # Programming HeaderPGC clock input1 PGD - data input/output44 /MCLR - Master Reset18 VDD40 VSS39 Shift RegisterSDO1 - SPI Data out44 SCK143 LCD ScreenRE5 - LCD Enable8 RF0 - Register Select5 RF TransceiverAN3 - RSSI22 RB0 - Data19 RB1 - T/R Select20 RB2 -Power down21 TriggerRF1 - trigger input4 IR LEDPWM1H14 Laser LEDRE2 - Gen I/O11 Color LED Set 1RC14 - Gen I/O35 Color LED Set 2RE8 - Gen I/O36 Photo Transistor Set 1IC1 - input capture42 Photo Transistor Set 2IC2 - input capture37 Photo Transistor Set 3IC8 - input capture24 Photo Transistor Set 4IC7 - input capture23

Trigger Circuit Pin is pulled up in static state When button is pressed, switch pulls pin to ground Pin is never floating in this configuration IR LED and laser connected to PWM to allow for set frequency pulsing NPN transistor as pull-down Transistor base connected to Micro to pulse to allow for larger drive current Pull up resistor to supply voltage

NPN transistor as pull-down Transistor base connected to microcontroller to pulse to allow for larger drive current Pull up resistor to supply voltage

Asserts low when 56kHz square wave pulse is detected; high otherwise Goes to input capture and triggers a software interrupt on an edge Parallel detectors for wider detection angles

 Considerations: ◦ RF ground plane ◦ No traces under transceiver ◦ Centrally placed microcontroller ◦ Noise reduction

3” x 5”

 RF communication protocol: Listen before transmit with random retry  IR protocol: Simple ID number transmission like television remote  Practicing with MPLab IDE by Microchip to create interrupts, run simple programs, and set up peripheral units  Using MPLab simulator to test chip functionality before PCB is assembled

WeekProjected Tasks 8Revise Schematic, Revise PCB, Learn MPLab IDE and Debugger 9Finalize PCB, Ensure all parts are on hand and fit PCB 10Spring Break 11RF and IR software communication stacks and protocol 12Game software and remaining software 13PCB Assembly 14Software and hardware debugging 15Final testing, user manual, demo preparation 16Final demonstration